Description (From Applicant's Abstract). This research will continue to explore the presentation of graphical, information to blind persons using a finger-tipped scanned electrotactile display. The increasing use of computer graphics and pictorial displays (such as the Apple Macintosh and Microsoft Windows environments) presents a major problem for blind computer users. While text output is available through speech synthesis and by small refreshable Braille displays, these techniques cannot present complex pictorial or spatial information, such as that embedded in organizational charts, computer programs or process flowcharts, electrical, architectural, or mechanical drawings, pictures, or visual artwork. The previous competitive segment of this project demonstrated that (1) controlled, localized touch sensations can be induced via electrical simulation on the fingertips, and (2) subjects can identify simple geometric patterns via haptic exploration of a matrix of small electrodes embedded in a flat plate. The proposed research seeks to further understand and advance this method of communicating spatial information. Possible future applications include telerobotic and virtual reality hand controllers as well as the primary focus of sensory rehabilitation. Specifically, the proposed work aims to: (1) develop improved fingertip-scanned electrode arrays using advance micromanufacturing techniques; (2) evaluate the performance of the fingertip tactile display (and additionally compare with an existing abdominal electrotactile display) for the presentation of complex spatial patterns using pattern discrimination techniques, evaluated by decision- theoretical models; (3) investigate and characterize two perceptual phenomena related to electrotactile displays: sensory adaptation and post- stimulus percept evaluated by measurement of sensory thresholds and also be cross-modality intensity matching; (4) electrode configuration in order to maximize spatial pattern discrimination performance; and (5) explore advanced waveform control methods to enhance the controllability of the electrotactile percept.